CN110870812B

CN110870812B - Device for repairing phalangeal joints, prosthetic metatarsophalangeal joint device and method for manufacturing a device for repairing phalangeal joints

Info

Publication number: CN110870812B
Application number: CN201910806027.2A
Authority: CN
Inventors: K·米姆诺; O·O·波普拉; J·E·菲利普斯
Original assignee: Zimmer Inc
Current assignee: Zimmer Inc
Priority date: 2018-08-29
Filing date: 2019-08-29
Publication date: 2021-12-07
Anticipated expiration: 2039-08-29
Also published as: US20210330468A1; US20200069434A1; CN110870812A; EP3653174A3; EP3653174A2; US11779467B2; US11076964B2

Abstract

The invention relates to a metatarsophalangeal joint replacement device and a method, wherein the device for repairing phalangeal joints comprises a first anchor, a second anchor and a flexible spacer connecting the first anchor and the second anchor. The flexible spacer includes a plurality of elongated fibers extending axially or crosswise between the first anchor and the second anchor and a polymer matrix interspersed with the plurality of elongated fibers. The prosthetic metatarsophalangeal joint device includes a porous metal metatarsal anchor, a porous metal phalanx anchor, and a polymeric spacer element including parallel or intersecting elongate fibers connecting the metatarsal anchor and the phalanx anchor. Methods of manufacturing prosthetic joint devices include using three-dimensional printing processes or molding processes. A method of implanting a prosthetic joint device includes positioning porous metal anchor assemblies at a planar interface adjacent resected bone and disposing a polymeric spacer having axially aligned elongated fibers embedded in a matrix between the porous metal anchor assemblies.

Description

Device for repairing phalangeal joints, prosthetic metatarsophalangeal joint device and method for manufacturing a device for repairing phalangeal joints

Technical Field

The present application relates generally to prosthetic implants for foot or hand joints. More particularly, the present application relates to a flexible cartilage replacement device that may be attached between two bones, such as may be used in an arthroplasty procedure for an interphalangeal joint (e.g., the metatarsophalangeal joint or the metacarpophalangeal joint).

Background

The loss or wear of cartilage between the bones of the joint can be characterized as osteoarthritis ("OA"). OA in the major joint of the big toe, the first metatarsophalangeal joint ("MTPJ 1"), sometimes causes intolerable pain and discomfort for the patient various metatarsophalangeal joint replacement devices have been developed for the first metatarsophalangeal joint (MTPJ 1).

One example of a metatarsophalangeal joint replacement device is a rigid connection assembly implanted in the intramedullary region of each bone between the opposing bones of the joint. In such a configuration, the bones typically fuse together. One example of such a device is described in detail in U.S. patent No. 8,920,453 to Tyber et al.

Another type of metatarsophalangeal joint replacement device utilizes a pair of components implanted into opposite bones so as to abut one another. The components are configured to slide relative to one another to create a non-fused articulating joint. One example of such a device is described in detail in U.S. publication No. 2017/0367838 to Cavanagh et al.

Another type of metatarsophalangeal joint replacement device utilizes a pad or cushion interposed between the bones. The pad or cushion is typically attached by an intramedullary insert that extends into the opposing bone. Examples of such devices are described in detail in U.S. Pat. No. 5,480,447 to Skiba, U.S. Pat. No. 5,879,396 to Walston et al, and U.S. Pat. No. 6,007,580 to Lehto et al.

Another type of metatarsophalangeal joint replacement device utilizes a pad or cushion that is positioned between the bones in place of the cartilage and can be connected to the bones by minimally invasive means. An example of such a device is described in detail in Patrick et al, U.S. Pat. No. 9,907,663.

Problems in conventional metatarsophalangeal joint replacement devices persist and may cause patient discomfort. Accordingly, there is a need for an interphalangeal (e.g., metatarsophalangeal) joint implant that reduces or eliminates pain, and provides better comfort and performance to the patient.

Disclosure of Invention

The inventors of the present application have recognized that problems to be solved in MTPJ1 devices may include, among others, being too stiff, feeling too loose, being overly invasive to implant, and inadequate coupling to bone. Thus, conventional MTPJ1 devices may feel unnatural to the patient. Some conventional metatarsophalangeal joint replacement devices often result in fusion of the joints, which results in joint stiffness and patient discomfort. Even without fusion, these devices may feel too tight (difficult to bend) or too loose for the patient (e.g., overarticulation of joints in Ehlers-Danlos syndrome: joints separate unnaturally), and the implant may loosen due to insufficient fixation to the bone. Some devices may also require extensive intramedullary implantation in both bones of the joint, which may complicate the arthroplasty procedure.

In particular, the polymer or hydrogel pads or spacers interposed between the metatarsals and the phalanges may be too stiff to reproduce natural flexion. In addition, these types of spacers can be difficult to attach to bone. For example, the spacer provides a small area for promoting bone ingrowth or cement bonding that may be difficult to deliver to the desired location of the joint.

The subject matter of the present application may help provide a solution to these and other problems, for example, by providing an interphalangeal joint device (e.g., MTPJ1 device) that may be securely attached to the metatarsals (or metacarpals) and phalanges (phalanges) without the need for invasive intramedullary manipulation, while also providing a degree of flexibility and tightness that may more closely replicate the natural joint, thereby providing better patient comfort and performance. Furthermore, the devices of the present disclosure can be manufactured in an easily implantable and easily customizable configuration.

In one example, a device for repairing a phalangeal joint may include a first anchor, a second anchor, and a flexible spacer. The flexible spacer may connect the first anchor and the second anchor, and may include a plurality of elongated fibers extending axially or crosswise between the first anchor and the second anchor, and a polymer matrix interspersed with the plurality of elongated fibers.

In another example, a prosthetic metatarsophalangeal joint device may include: a metatarsal or metacarpal anchor which may comprise a porous metal material; a phalanges anchor that may include a porous metal material; and a polymeric spacer element that may connect the metatarsal anchors and the phalangeal anchors. The polymeric spacer element may include a plurality of elongated fibers extending parallel or crosswise between the metatarsal anchors and the phalange anchors.

In further examples, a method of manufacturing a device for repairing a phalangeal joint may include: fabricating a first anchor assembly and a second anchor assembly using a first additive manufacturing process (e.g., 3D printing) to create a porous structure within each assembly; fabricating a flexible spacer assembly using a second additive manufacturing process or a molding process to produce a plurality of elongated fibers extending directly or crosswise through the flexible spacer; and attaching opposite ends of the flexible spacer assembly to the first and second anchor assemblies.

The purpose of this summary is to provide an overview of the subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application.

Drawings

Fig. 1 is a diagram illustrating a prosthetic joint device of the present disclosure implanted in a first metatarsophalangeal joint of a foot.

FIG. 2 is a schematic view illustrating a prosthetic joint device of the present disclosure including a flexible spacer connecting two anchor assemblies positioned between opposing bones.

FIG. 3 is a schematic view illustrating another embodiment of the prosthetic joint device of the present disclosure including a flexible spacer comprising elongated fibers and an anchor assembly comprising fixation pins.

FIG. 4 is a cross-sectional view of the flexible spacer of FIG. 3 showing a plurality of polymer fibers disposed in a polymer matrix.

Fig. 5 is a cross-sectional view of the anchor assembly of fig. 3 showing a metal porous structure comprised of cell ribs and pores.

Fig. 6 is a diagram showing the anatomy of the first metatarsophalangeal joint.

Fig. 7 is a diagram illustrating the positioning of resected bone for implantation of a prosthetic joint device of the present disclosure.

FIG. 8 is a diagram illustrating an implanted prosthetic joint device of the present disclosure implanted into the resected bone of FIG. 7.

Fig. 9 is a line drawing illustrating steps of a method for manufacturing the prosthetic joint device of the present disclosure.

Fig. 10 is a line drawing illustrating steps of a method for implanting a prosthetic joint device of the present disclosure.

FIG. 11 is a schematic view illustrating a prosthetic joint implant of the present disclosure including electronic circuitry.

In the drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate by way of example, and not by way of limitation, various embodiments discussed in the present document.

Detailed Description

Fig. 1 is a diagram illustrating a prosthetic joint device 10 implanted in a foot 12 at a first metatarsophalangeal joint (MTPJ1) 14. The foot 12 includes five phalanges, each of which includes one or both of a distal phalanx and a proximal phalanx, and a metatarsal phalanx. For example, the first metatarsophalangeal joint 14 includes a distal phalange 16, a proximal phalange 18, and a metatarsophalangeal bone 20. The prosthetic joint device 10 may include a flexible spacer 22, a first anchor assembly 24A and a second anchor assembly 24B.

The prosthetic joint device 10 may be used to reproduce the natural or anatomical operation of a joint between two bones of the foot 12. In the example shown, the prosthetic joint device 10 is used in the MTPJ 114 between the proximal phalanx 18 and the metatarsophalangeal bone 20, but it could be used in any of the phalanges of the foot 12. In addition, the prosthetic joint device 10 may be used to repair or replace other small skeletal joints (e.g., the metacarpal joints of the hand).

A healthy anatomical MTPJ1 joint includes cartilage as the epiphyseal part of each bone (see fig. 6). The cartilage, along with joint fluid, provides a cushion between each bone that also facilitates joint flexion. With age and due to trauma, cartilage may wear or deteriorate, resulting in joint pain and stiffness. The prosthetic joint device 10 may be implanted into a joint to reduce pain and restore proper joint flexibility and mobility. In particular, the anchor assemblies 24A and 24B may provide secure anchoring of the prosthetic joint device 10 to the

bones

18 and 20 through osseointegration, and the flexible spacer 22 may hold the MPJ 114 joint together in the anterior-posterior direction while also providing flexion in the sagittal plane.

The first and second anchor assemblies 24A, 24B may be attached to the proximal phalanx 18 and the metatarsophalangeal bone 20, respectively. In various examples, the components 24A and 24B may be constructed of a porous metal material (e.g., porous titanium or tantalum). The flexible spacer 22 may be positioned between the components 24A and 24B and connected to the components 24A and 24B. In various examples, the spacer 22 can include a polymeric component having an anterior-posterior arrangement of fibers that can be embedded in a polymeric matrix to provide flexibility to the device.

Fig. 2 is a schematic diagram showing a prosthetic joint device 30, the prosthetic joint device 30 including a flexible spacer 32 connecting a first anchor assembly 34A and a second anchor assembly 34B, the first anchor assembly 34A and the second anchor assembly 34B being connected to the proximal phalanx 18 and the metatarsophalangeal bone 20, respectively. In general, the device 30, as well as other embodiments of the present application, may include two opposing anchor assemblies (e.g.,

assemblies

34A and 34B) that may be used to provide attachment to the bone, and a central cushion assembly (e.g., flexible spacer 32) that may provide articulation of the joint and provide flexibility to the joint.

In one example, the device 30 may be manufactured in multiple processes such that the device 30 is a single integrated body of multiple materials. In such a configuration, flexible spacer 32 may be produced using a polymer using an additive manufacturing process or a molding process, while

anchor assemblies

34A and 34B may be produced using a metal using a separate additive manufacturing process. However, in various examples, the prosthetic joint device 30 may be constructed of a single unitary structure or a plurality of different components attached together. The prosthetic joint device 30 may also be constructed from a single type of material or multiple material types. For example, the device 30 may be manufactured in a single process such that the device 30 is only an integral piece of polymeric material. In another example, device 30 may be manufactured using a single process such that device 30 comprises an entirety of multiple materials.

Additive manufacturing processes, such as three-dimensional (3D) printing techniques (e.g., electron beam or laser additive manufacturing), can be used to produce porous metal structures of titanium alloy or tantalum having geometries that facilitate osseointegration and that can also produce intricate elongated fibers in a desired orientation. Furthermore, the additive manufacturing process allows one or more components of the apparatus 30 to be built directly on one or more other components. As such, the first and

second anchor assemblies

34A, 32 can be made of a porous metal material to facilitate attachment to bone, while the flexible spacer 32 can be made of a polymer material including fibers to facilitate flexion. The specific shape and geometry of

anchor assemblies

34A and 34B and spacer 32 can vary according to design needs. For example,

anchor assemblies

34A and 34B and spacer 32 can have a circular, rectangular, square, or polygonal cross-sectional profile. In one example, the

anchor assemblies

34A and 34B and the spacer 32 have a hexagonal cross-sectional profile, as shown in fig. 4 and 5. The hexagonal profile may facilitate implantation into bone by providing sufficient planar surface area for bone contact and also providing edges for resisting rotation within the bone.

Fig. 3 is a schematic diagram illustrating a prosthetic joint device 40 of the present disclosure, the prosthetic joint device 40 including a flexible spacer 42 and

anchor assemblies

44A and 44B coupled between the proximal phalanx 18 and the metatarsophalangeal bone 20. The flexible spacer 42 may include elongated fibers 46, a matrix 48, and

interdigitation regions

50A and 50B. Anchor assembly 44A may include a base 52A and

fixation pegs

54A and 56A. Anchor assembly 44B may include a base 52B and fixation pegs 54B and 56B.

The base 52A of the anchor assembly 44A may include a disc-shaped body for supporting the flexible spacer 42 and facilitating attachment to the proximal phalanx 18. The rear surface 58A may be flat or substantially flat to provide a base upon which the interdigitation region 50A may be positioned and built from. Likewise, the anterior surface 60A may be flat to enhance bony contact with the proximal phalanges 18, and the proximal phalanges 18 may be partially resected to provide a flat bony surface. The fixation nails 54A and 56A may extend from the anterior surface 60A at a location to allow insertion of the

fixation nails

54A and 56A into the cancellous bone of the proximal phalanx 18. Thus, fixation pegs 54A and 56A increase the surface area of anchor assembly 44A in contact with bone to enhance osseointegration, as well as provide initial fixation of anchor assembly 44A to bone 18.

The base 52B of the anchor assembly 44B may include a disc-shaped body for supporting the flexible spacer 42 and facilitating attachment to the metatarsal phalanges 20. The front surface 60B may be flat or substantially flat to provide a base upon which the interdigitation region 50B may be positioned and built from. Likewise, the posterior surface 58B may be flat to enhance bone contact with the metatarsophalangeal bone 20, and the metatarsophalangeal bone 20 may be partially resected to provide a flat bone surface. The fixation pins 54B and 56B may extend from the posterior surface 58B at a location to allow insertion of the fixation pins 54B and 56B into the cancellous bone of the metatarsal phalangeal 20. Thus, fixation pegs 54B and 56B increase the surface area of anchor assembly 44B in contact with bone to enhance osseointegration, as well as provide initial fixation of anchor assembly 44B to bone 20.

The geometry of

anchor assemblies

44A and 44B may be identical and may be interchangeable such that

anterior surfaces

60A and 60B and

posterior surfaces

58A and 58B, respectively, may be reversed.

As discussed, the

bases

52A and 52B may have various cross-sectional profiles. In addition, the cross-sectional profile of the

staples

54A, 56A, 54B and 56B may have various cross-sectional profiles, such as circular, rectangular, square, polygonal, hexagonal and ribbed cross-sectional profiles. As described above, the rear surface 58A and the front surface 60B may be flat to facilitate bonding with the

interdigitation regions

50A and 50B, respectively.

The

interbonded regions

50A and 50B may include solid materials that may facilitate coupling of the elongated fibers 46 to the

bases

52A and 52B, respectively. For example, the interdigitation region 50A may comprise a disc of material having a front surface 62A and a rear surface 64A, the front surface 62A may be fused into the aperture of the base 52A, and the fibers 46 may extend integrally from the rear surface 64A. Likewise, the interdigitation region 50B may comprise a disk of material having a back surface 64B and a front surface 62B, the back surface 64B may be fused into the aperture of the base 52B, and the fibers 46 may extend integrally from the front surface 62B.

Fibers 46 may extend from first interbonded region 50A to second interbonded region 50B. In one example, all of the fibers 46 are parallel or substantially parallel to each other. The fibers 46 may extend parallel to the axis a of the device 40. Axis a may extend along a longitudinal midline of

anchor assemblies

44A and 44B, which may coincide with an anatomical midline of

bones

18 and 20. The matrix 48 material may be sandwiched between the

interbonded regions

50A and 50B and filled between the fibers 46. The material of the matrix 48 may be in contact with the fibers 46 but not bonded to the fibers 46. The coupling of the

interdigitation regions

50A and 50B to the

bases

52A and 52B, respectively, and the fibers 46 provide axial, fore-aft stability and attachment of the device 40. In addition, the fibers 46 allow the flexible spacer 42 to flex because the material of the matrix 48 can slide over and around the fibers 46 in a deflected state. In this way, the device 40 can reproduce the feel and flexibility of an anatomical joint.

FIG. 4 is a cross-sectional view of the flexible spacer 42 of FIG. 3 showing a plurality of fibers 46 disposed in a matrix 48. The dimensions and spacing of the fibers 46 relative to the depicted cross-section are not drawn to scale and are shown for illustrative purposes. The fibers 46 may have a circular cross-sectional profile to facilitate bending, but other shapes may be used. In an example, the diameter of the fibers 46 may be in the range of about 0.4nm to about 100 nm. In other examples, the fibers 46 may have other cross-sectional profiles. The fibers 46 may be separated from one another to provide space for the matrix 48. In an example, the fibers 46 may be spaced at intervals in the range of about 0.01mm to about 2 mm. The fibers 46 may be uniformly or asymmetrically or crosswise spaced. The crossing and spacing of the fibers 46 may be used to adjust the stiffness of the flexible spacer 42. For example, as shown in fig. 8, the flexible spacers 42 may be more densely spaced near the bottom or underside of the device to facilitate bending in the superior direction. In one example, the fibers 46 and the matrix 48 may comprise a polyethylene material. In an example, the fibers 46 may occupy from about 20% to about 70% of the cross-sectional area. Such a ratio may provide the flexible spacer 42 with sufficient stiffness to compress, stretch, and twist, but facilitate the flexible spacer 42 to bend in a manner that closely reproduces the operation of a natural joint. Matrix 48 may include a polymeric material loosely wrapped around fibers 46 and between fibers 46. In one example, the material of the matrix 48 forms a pseudo-tube around the fibers 46 that helps keep the fibers 46 separated and provides resistance to axial compression of the fibers 46, but does not inhibit buckling of the fibers 46.

Fig. 5 is a cross-sectional view of the anchor assembly 44A of fig. 3 showing the metal porous structure comprised of the ribs 66 and pores 68. The dimensions and spacing of the ribs 66 and apertures 68 relative to the depicted cross-section are not drawn to scale and are shown for illustrative purposes. The ribs 66 are configured to provide structural stability to the anchor assembly 44A while creating apertures 68, the apertures 68 reducing the weight of the assembly 44A and providing space for osseointegration with the bone and fusion with the interdigitation region 62A (fig. 3). In the depicted example, the ribs 66 and pores may reproduce the geometry of the anatomical bone. In other examples, the ribs 66 and apertures 68 may have other geometries or a composite geometry.

The anchor assembly 44A may be formed of a suitable material that promotes bone ingrowth and is biocompatible (e.g., a porous metal material, or a porous tantalum material having a porosity of about 20% -80% and a pore size of about 50-600 μm, or any range of porosities and pore sizes defined between any pair of the aforementioned values, for example). An example of a highly porous tantalum and titanium alloy material is Trabeculator Metal, commonly available from Zimmer Biomet of Wash, Ind^TMAnd OsseoTi^TM. Both materials are trademarks of Zimmer Biomet.

The anchor assembly 44A can be formed by a number of different processes. In one example, such a material may be formed from a reticulated vitreous carbon foam substrate infiltrated and coated with a biocompatible metal (e.g., tantalum) by a Chemical Vapor Deposition (CVD) process in the manner disclosed in detail in U.S. patent No. 5,282,861 to Kaplan, the disclosure of which is expressly incorporated herein by reference in its entirety for all purposes. In addition to tantalum, other metals (such as niobium, or alloys of tantalum and niobium with each other or with other metals) may also be used. The tantalum metal film and carbon substrate combination can be used to fabricate an open-pore metal structure (where the film is deposited by CVD) that closely mimics bone by having ribs interconnected to form open spaces or pores 68.

In an example, the anchor assembly 44A and other prosthetic components described herein having a metallic porous structure (including pores and pores such as those described herein, etc.) can be provided by any number of suitable three-dimensional porous structures, and these structures can be formed from one or more of a variety of materials (including, but not limited to, subsequently pyrolyzed polymeric materials, metals, metal alloys, ceramics). In some cases, Selective Laser Sintering (SLS) or other additive modeling processes (e.g., direct metal laser sintering) will be used to fabricate highly porous three-dimensional structures. In one example, a three-dimensional porous article is made in a layered fashion from laser-fusible powders (e.g., polymer material powders or single component metal powders) deposited one layer at a time. The powder is fused, remelted, or sintered by applying laser energy directed to portions of the powder layer corresponding to the article cross-section. After fusing the powder in each layer, a further layer of powder is deposited and a further fusing step is performed, fusing by fusing parts or lateral layers, to fuse parts of the previously laid layer, until the three-dimensional article is completed. In certain embodiments, the laser selectively fuses the powdered material on the powder bed surface by scanning a cross-section generated from a 3-D digital description of the article (e.g., from a CAD file or scan data). In some cases, the net shape and near net shape are infiltrated and coated.

Complex geometries can be created using these techniques. In some cases, the three-dimensional porous structure will be particularly suitable for contacting bone and/or soft tissue, and in this regard, may be used as a bone substitute and material that cells and tissue are able to accept (e.g., by allowing tissue to grow into the porous structure over time to enhance fixation (i.e., osseointegration) between the structure and surrounding bodily structures to provide a matrix approximating natural cancellous bone or other skeletal structure). In this regard, the three-dimensional porous structure, or any region thereof, can be fabricated to nearly any desired density, porosity, pore shape, and pore size (e.g., diameter of the pores). Thus, the structure may be isotropic or anisotropic.

The structure may be infiltrated and coated with one or more coating materials. When coated with one or more biocompatible metals, any suitable metal (including any of the metals disclosed herein, such as tantalum, titanium alloys, cobalt chromium molybdenum, tantalum alloys, niobium, or alloys of tantalum and niobium with each other or with other metals) may be used. In various examples, the three-dimensional porous structure may be fabricated to have substantially the same porosity, density, pore shape, and/or pore (pore) size throughout the structure, or to include at least one of a pore shape, pore size, porosity, and/or density that varies within the structure. For example, the three-dimensional porous structure to be infiltrated and coated may have different pore shapes, pore sizes, and/or porosities at different regions, layers, and surfaces of the structure.

In some embodiments, a non-porous or substantially non-porous base substrate will provide a matrix upon which a three-dimensional porous structure will be built and fused thereto using a Selective Laser Sintering (SLS) or other additive manufacturing type process. Such a substrate may comprise one or more of a variety of biocompatible metals (e.g., titanium alloys, cobalt chromium molybdenum, tantalum, or tantalum alloys).

In an example, the anchor assembly 44A may comprise titanium fabricated using a rapid manufacturing process. In an example, the rapid manufacturing process may include an additive manufacturing process (e.g., a powder deposition process). In such a process, very thin layers of powdered titanium (e.g., layers that are only as thick as several layers of particles of powdered titanium) may be laid down layer by layer. At each increment, selective portions of the powdered titanium may be solidified to form a portion of the anchor assembly 44A, and the uncured particles may be left to support the next layer of powder. For example, a laser may be used to selectively melt the portion of the powdered titanium layer that will form the anchor assembly 44A. Subsequently, a new layer of titanium powder particles may be laid on top of the previous partially cured layer, and additional curing processes may take place. These steps may be repeated until anchor assembly 44A is built from one end to the other. The uncured particles may then be removed. Other types of rapid manufacturing processes (e.g., 3D printing processes) may be used to fabricate the prosthetic joint device 40.

A rapid manufacturing process may be used to include the desired level of porosity directly into the anchor assembly 44A. Likewise, the rebar 66 can be made to have any desired shape, size, number, and aggregate strength and density to create sufficient bond strength to survive implantation and operation of the anchor assembly 44A while allowing for the injection of the bone and polymer material of the interdigitation region 50A, as described herein.

Fig. 6 is a diagram illustrating the natural anatomy 70 of the first metatarsophalangeal joint 14 of fig. 1 (which may include the proximal phalanx 18 and the metatarsophalangeal bone 20). Also, as noted above, the devices and methods described herein may be applied to other anatomical structures (e.g., metacarpal joints of the hand). The anatomy 70 may include

articular cartilage pads

72A and 72B on the ends of

bones

18 and 20, respectively. The joint capsule may be filled with synovial fluid 74 encapsulated in synovial membrane 76. In the case of osteoarthritis ("OA"),

cartilage pads

72A and 72B may become worn and/or hardened, which may cause pain and discomfort to the patient as the ends of

bones

18 and 20 rub against each other. Thus, it may be desirable to reproduce the natural feel and motion of the

cartilage pads

72A and 72B using a prosthetic joint device configured in accordance with the embodiments and examples described herein. To begin arthroplasty of the metatarsophalangeal joint 14, an incision may be made through the skin 78 and synovium 76 to expose the

cartilage pads

72A and 72B. Joint 14 may flex to expose opposite ends of

bones

18 and 20, as shown in fig. 7.

Fig. 7 is a diagram illustrating the positioning of resected

bones

18 and 20 for implantation of a prosthetic joint device 40 of the present disclosure in a first metatarsophalangeal joint 14. The proximal phalanx 18 may flex substantially transverse to the metatarsophalangeal bone 20. The distal end 80 of the metatarsal phalangeal 20 can be partially cut away to form a planar front surface 82. The proximal end 84 of the proximal phalanx 18 may be partially cut away to form a planar posterior surface 86. In this way, the

cartilage pads

72A and 72B may be removed and cancellous bone within the

bones

18 and 20 may be exposed at the

surfaces

82 and 86 and located within the hard cortical walls of the

bones

18 and 20. The prosthetic joint device 40 may be flexed at the flexible spacer 42 such that the fixation pegs 54B and 56B may be press fit into the cancellous bone of the surface 82 and the fixation pegs 54A and 56A may be press fit into the cancellous bone of the surface 86.

Fig. 8 is a diagram illustrating an implanted prosthetic joint device 40 of the present disclosure implanted into the resected

bones

18 and 20 of fig. 7. The prosthetic joint device 40 may include a first anchor assembly 44A, a second anchor assembly 44B, and a flexible spacer 42. The fixation nails 54A and 56A of the first anchor assembly 44A may be inserted into the cancellous bone of the planar posterior surface 86 such that the anterior surface 60A of the base 52A is flush against the planar posterior surface 86. The fixation nails 54B and 56B of the second anchor assembly 44B may be inserted into the cancellous bone of the planar anterior surface 82 such that the posterior surface 58B of the base 52B is flush against the planar anterior surface 82. The flush engagement between surface 86 and surface 60A and surface 82 and surface 58B may contribute to the stability of the prosthetic joint device 40 and may promote bone ingrowth into the

anchor assemblies

44A and 44B, respectively.

The prosthetic joint device 40 may be sized to fit within the MPJ 114. In an example, the prosthetic joint device 40 may have a single size configured to fit most or all of the different sized bones of the general population. In other examples, the prosthetic joint device 40 may have a variety of sizes (e.g., small, medium, and large) to allow for semi-custom sizes to be provided. In other examples, the prosthetic joint device may be sized for a patient-specific application (e.g., by measuring the dimensions of

bones

18 and 20 from pre-operative images).

In an example, the length of the prosthetic joint device 40 between the

surfaces

58B and 60A may be approximately equal to the length of the resected portions of the

bones

18 and 20 plus the thickness of the

cartilage pads

72A and 72B (e.g., average for a typical adult human). In an example, the diameter of the

bases

52A and 52B may be designed to be approximately equal to the diameter of the

bones

18 and 20 at the joint 14 (e.g., average for a typical adult human).

Fig. 9 is a line drawing illustrating steps of a method 100 for manufacturing a prosthetic joint device (e.g., prosthetic joint device 40) of the present disclosure. In step 102, the dimensions of joint 14 (FIG. 1) may be determined. For example, the diameters of the proximal phalanges 18 and metatarsophalangeal bones 20 may be measured from preoperative images of the joint 14. The pre-operative images may include x-ray images, CT images, MRI images, etc., as well as two-dimensional and three-dimensional computer-generated models derived from the pre-operative images. From this measurement, the diameter of the

bases

52A and 52B (FIG. 3) can be determined. In addition, joint length (e.g., thickness of

cartilage pads

72A and 72B) may be measured. From this measurement, the combined length of the flexible spacer 42 and the

bases

52A and 52B can be determined. The measured dimensions of the joint 14 may be used to customize the prosthetic joint device 40 to fit a particular patient, or may be used to select from a range of predetermined dimensions of the prosthetic joint device 40. Step 102 may be an optional step. For example, the prosthetic joint device 40 may be manufactured from anatomical data of a typical adult and may be configured for use with a typical adult without measurement. In further examples, measurements of the joint 14 may be made intraoperatively by a surgeon or other person to determine dimensions from a pre-fabricated prosthetic joint device.

In step 104, the

porous anchor assemblies

44A and 44B (fig. 3) can be fabricated, for example, by using a three-dimensional ("3D") printing process. In one example, the

bases

52A and 52B and the pegs 54A-56B may be constructed using a selective laser sintering process. These components may include ribs 66 and apertures 68. The

components

44A and 44B may be made of various materials (e.g., polymeric materials and metallic materials). The

bases

52A and 52B may be sized (e.g., length and diameter) based on the measurements made in step 102. In an example, the

components

44A and 44B are made of a titanium alloy, a stainless steel alloy, and a tantalum alloy.

In step 106, the flexible spacer 42 may be manufactured, for example, by using a 3D printing process or a molding process, or a combination of both. In one example, a fuse fabrication process may be used to construct the

interdigitation regions

50A and 50B, the fibers 46, and the matrix 48. In particular, one of the

interdigitation regions

50A and 50B may be built directly on top of one of the

bases

52A and 52B, respectively. In such a process, for example, the polymeric material of the interdigitation regions 50A may be deposited onto the apertures 68 of the base 52A and/or melted into the apertures 68 of the base 52A, thereby causing adhesion of the interdigitation regions 50A to the base 52A. The interdigitation zone 50A may be constructed to a sufficient thickness to cover or substantially cover the desired surface area of the base 52A. In this way, a planar surface of polymeric material may be built up on the base 52A to support the fibers 46. In an example, the interdigitation regions 50A may be made of a polymeric material (e.g., polyethylene). In another aspect of the present disclosure, the polymer and antibiotic powder mixture may be used to 3D print out the intercalated polymer of the flexible spacer 42 between two metal stents formed by the

porous anchor assemblies

44A and 44B. The antibiotic may elute from the polymeric material and out of the implant into the patient, for example, to prevent and treat possible infections. The antibiotic powder may be azithromycin, amoxicillin, gentamicin or other similar medication.

In step 108, fibers 46 may be built onto the interbonded regions 50A. The fibers 46 may be integrally constructed with the interbonded regions 50A. In step 110, the material of the matrix 48 may be deposited around the fibers 46. The fibers 46 and matrix 48 can be built up simultaneously to the desired length on top of the interbonded region 50A. The fibers 46 and matrix 48 may be made to length based on the measurements made in step 102. The material of the matrix 48 may be positioned around the fibers 46 without being attached to the fibers 46 to facilitate flexing of the flexible spacer 42. In an example, the fibers 46 and the matrix 48 may be made of a polymeric material (e.g., polyethylene). In an example, the fibers 46 and the matrix 48 can be made of the same or different materials from each other.

In step 112, the interbonded regions 50B may be constructed on the ends of the fibers 46 and on top of the matrix 48. For example, the material layer of the flexible assembly 42 may be formed to bundle the ends of the fibers 46 and form a base for bonding with the second anchor assembly 44B. In an example, the interdigitation regions 50B may be made of a polymeric material (e.g., polyethylene).

In step 114, the interdigitation region 50B and the second anchor assembly 44B may be attached to one another. In one example, the interdigitation region 50B may be constructed to a desired thickness, and the anchor assembly 44B may be attached to the interdigitation region 50B, for example, by being pushed into the material of the interdigitation region 50B to cause the material to penetrate into the apertures 68. In an example, the interbonded regions 50B may be constructed directly on the base 52B and attached to the fibers 46 and matrix 48.

Steps 102-114 describe example method steps for forming a prosthetic joint device to include a plurality of elongate fibers. Such elongated fibers may be configured in a parallel or crossed axial manner to extend between the anchor assemblies. The elongated fibers may be continuous between anchor assemblies to provide axial or fore-aft strength to the device. In addition, the diameter of the elongated fibers allows the device to easily flex in the sagittal plane. The presence of the matrix material alongside the elongate fibers provides stability to the elongate fibers to prevent the device from buckling (e.g., the device collapses together in the anterior-posterior direction). However, the presence of the matrix material does not stiffen the device in the sagittal plane. Such fibers and matrix compositions may be produced using additive manufacturing techniques described herein. However, in other examples, a manufacturing process (e.g., a molding process) capable of producing the fibers and matrix compositions described herein may be used.

Fig. 10 is a line drawing illustrating steps of a method 200 for implanting a prosthetic joint device (e.g., prosthetic joint device 40) of the present disclosure. Steps 202-214 provide a high level overview of the steps that may be taken to implant the prosthetic joint device 40 and are not intended to be an exhaustive list. In other examples, other steps may be used.

In step 202, an incision may be made in the patient's tissue to expose

bones

18 and 20 of MTPJ 114. Specifically, the skin 78 and the sac 76 may be cut to expose the

cartilage pads

72A and 72B (if the pads were not worn away by osteoarthritis), as shown in FIG. 6.

In step 204, the surgeon or others may flex the MTPJ 114 to expose the distal end of the proximal phalanx 18 and the metatarsophalangeal bone 20, as shown in fig. 7. In such a position,

cartilage pads

72A and 72B may be exposed and distal end 80 and proximal end 84 (fig. 7) may be easily visible to the surgeon.

At step 206,

bones

18 and 20 may be partially resected to form a planar posterior surface 86 and a planar anterior surface 82, respectively, as shown in fig. 7. The

bones

18 and 20 can be partially resected to form a flat or planar surface against which the surfaces of the

anchor assemblies

44A and 44B can abut. Additionally, the

bones

18 and 20 may be partially resected to expose cancellous bone into which the fixation nails 54A-56B (FIG. 3) may be implanted.

In step 208, any desired measurements of the

bones

18 and 20, the

surfaces

86 and 82, and the gap between the

surfaces

86 and 82 may be made for use in the sizing of the prosthetic joint component. For example, if an off-the-shelf or standard implant is to be used, the surgeon may intraoperatively measure or observe the dimensions of the

bones

18 and 20 to determine which size of prosthetic joint device 40 is to be used from a set of standard sized devices.

In step 210, any anchor members of the prosthetic joint device 40 may be connected to the

bones

18 and 20. For example, as shown in fig. 8, the

fixation nails

54A and 56A of the anchor assembly 44A may be inserted into cancellous bone at the surface 86 of the bone 18, and the fixation nails 54B and 56B of the anchor assembly 44B may be inserted into cancellous bone at the surface 82 of the bone 20. The surgeon may flex or bend the flexible spacer 42 to attach all of the staples 54A-56B simultaneously. Thereafter, the tension on the flexible spacer may be released and the fibers 46 of the flexible spacer may relax and return to a natural, unflexed state such that the bone 18 may move into axial alignment with the bone 20, as shown in fig. 8.

In step 212, any bone cement may be applied to

anchor assemblies

44A and 44B, if desired. The application of bone cement may be optional if the surgeon can determine that sufficient bone material is present to support the fixation pins 54A-56B. Likewise, the fit of the prosthetic joint device 40 or any other observation of flexion of the repaired joint 14 may be observed and evaluated post-implantation.

In step 214, any incisions formed in step 202 may be closed, if desired or deemed appropriate by the surgeon.

Fig. 11 is a schematic diagram illustrating a prosthetic joint implant 300 of the present disclosure including electronic circuitry 306. The electronic circuitry 306 may be in communication with the reader 302 and the computer system 304. The prosthetic joint implant 300 may include a polymer layer 308 disposed between

porous scaffolds

310A and 310B. Electronic circuitry 306 may include

capacitor layers

312A and 312B, insulator 314, and resistor 316. The components of the prosthetic joint implant 300 are not drawn to scale.

Porous scaffolds

310A and 310B and polymer layer 308 can be configured according to the devices described herein. The electronic circuitry 306 may include a current version of the prosthetic joint implant that may convey information from the patient. Electronic circuitry 306 may include one or more capacitors formed by

capacitor layers

312A and 312B and insulator 314, as well as one or more of resistor 316 and other electronic components. The electronic component 3D may be printed onto the interface between the metal

porous scaffolds

310A and 310B and the polymer layer 308 to measure stress and strain during activities of daily living.

Capacitor layers

312A and 312B may comprise conductive plates, which may be made of tantalum, silver, or niobium, while insulator 314 may comprise a dielectric, which may be made of a polymer or ceramic material. The resistor 316 may be printed from carbon and ceramic powder.

Information or data relating to the measurements made by the electronic circuitry 306 may be conveyed to the reader 302. The reader 302 may be configured to wirelessly communicate with the electronic circuitry 306. In an example, reader 302 may also have write capability to send information to electronic circuitry 306. In this case, the electronic circuitry 306 may include a receiver and an electronic storage device. In this manner, patient-specific information may be written into the prosthetic joint implant 300. Information obtained from electronic circuitry 306 may be transferred to computer system 304 where the data may be stored and analyzed. The stress and strain may be analyzed to determine the condition of the prosthetic joint implant 300 and to assess the patient's lifestyle.

Various comments and examples

Example 1 may include or use a subject, such as an apparatus for repairing a phalangeal joint, which may include a first anchor, a second anchor, and a flexible spacer connecting the first anchor and the second anchor. The flexible spacer may include a plurality of elongated fibers extending between the first anchor and the second anchor, and a polymer matrix interspersed with the plurality of elongated fibers.

Example 2 may include the subject matter of example 1 or optionally combined with the subject matter of example 1 to optionally include a flexible spacer and a first anchor and a second anchor that may be integral with each other.

Example 3 can include or optionally be combined with the subject matter of one or any combination of examples 1 or 2 to optionally include a first anchor and a second anchor that can be comprised of a porous structure.

Example 4 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 3 to optionally include: the first anchor is connected to a first end of the flexible spacer by a first interdigitation region of the plurality of elongated fibers and polymer matrix that transitions the porous structure of the first anchor to the flexible spacer; and the second anchor is connected to a second end of the flexible spacer by a second interdigitation region of the plurality of elongated fibers and polymer matrix that transitions the porous structure of the second anchor to the flexible spacer.

Example 5 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 4 to optionally include: the first and second interdigitation regions extend into the apertures of the first and second anchors and are free of fibers of the plurality of elongated fibers.

Example 6 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 5 to optionally include: the flexible spacer is comprised of a polymer composition and the first and second anchors are comprised of a porous metal structure.

Example 7 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 6 to optionally include: the flexible spacer includes fibers of the plurality of fibers in a range of about 20% to about 70% of a volume of the flexible spacer.

Example 8 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 7 to optionally include: the first anchor and the second anchor each include one or more fixation staples.

Example 9 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 8, to optionally include: the fibers of the plurality of elongated fibers are spaced apart from one another by the polymer matrix.

Example 10 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 9, to optionally include: fibers of the plurality of fibers extend parallel to central axes of the first and second anchors in an unflexed state.

Example 11 may include or optionally be combined with the subject matter of one or any combination of examples 1 to 10 to optionally include: fibers of the plurality of fibers extend crosswise relative to each other and to central axes of the first and second anchors in an unflexed state.

Example 12 may include or use a subject matter, such as a prosthetic metatarsophalangeal joint device, which may include: a metatarsal anchor which may comprise a porous metal material; a phalanges anchor that may include a porous metal material; and a polymeric spacer element that may connect the metatarsal anchor and the phalanx anchor, the polymeric spacer element may include a plurality of elongate fibers extending between the metatarsal anchor and the phalanx anchor.

Example 13 may include the subject matter of example 12, or optionally in combination with the subject matter of example 12, to optionally include: first and second fixation pins extending from the metatarsal anchor and the phalangeal anchor, respectively; a polymeric matrix material interspersed with fibers of the plurality of elongated fibers; and an interdigitation region fusing the porous metal material of the metatarsal anchor and the phalange anchor with a fiber of the plurality of elongated fibers.

Example 14 may include or use a subject matter, such as a method of manufacturing a device for repairing a phalangeal joint. The method can comprise the following steps: fabricating a first anchor assembly and a second anchor assembly using a first additive manufacturing process to create a porous structure within each assembly; fabricating a flexible spacer assembly using a second additive manufacturing process or a molding process to produce a plurality of elongated fibers extending through the flexible spacer; and attaching opposite ends of the flexible spacer assembly to the first and second anchor assemblies.

Example 15 may include the subject matter of example 14 or optionally combined with the subject matter of example 14 to optionally include: fabricating the first and second anchor assemblies using the first additive manufacturing process by printing the assemblies from different materials and fabricating the flexible spacer assembly using the second additive manufacturing process or the molding process.

Example 16 may include or optionally be combined with the subject matter of one or any combination of examples 14 or 15 to optionally include: printing the first and second metal porous anchor assemblies by selective laser sintering from metal powder or electron beam based three-dimensional printing of first and second metal porous anchor assemblies.

Example 17 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 16 to optionally include: fabricating the flexible spacer assembly using the second additive manufacturing process by three-dimensionally printing or molding the flexible spacer from polyethylene.

Example 18 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 17, to optionally include: fabricating a flexible spacer assembly using a second additive manufacturing process or molding process to produce a plurality of elongated fibers extending through the flexible spacer by extending the fibers directly through or extending the fibers in an intersecting manner.

Example 19 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 18, to optionally include fabricating the flexible spacer assembly using the second additive manufacturing process or the molding process by: fusing a first interdigitation region into the first anchor assembly; building a plurality of elongated fibers from the interbonded regions; interspersing a matrix layer between fibers of the plurality of fibers; building a second interbonded region onto the plurality of elongated fibers and the matrix layer; and fusing the second interdigitation region into the second anchor assembly.

Example 20 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 19, to optionally include: fabricating the first anchor assembly and the second anchor assembly using the first additive manufacturing process to produce the porous structure within each assembly by producing a plurality of tendons interconnected to form an open space.

Example 21 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 20 to optionally include: fabricating the flexible spacer assembly using the second additive manufacturing process by three-dimensionally printing or molding the flexible spacer to include antibiotic powder.

Example 22 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 21, to optionally include: fabricating the flexible spacer assembly using the second additive manufacturing process by three-dimensionally printing or molding the flexible spacer to include electronic circuitry.

Example 23 may include or optionally be combined with the subject matter of one or any combination of examples 14 to 22, to optionally include: fabricating the flexible spacer assembly using the second additive manufacturing process by three-dimensionally printing or molding the flexible spacer to include electronic circuitry that can measure stress and strain in the device.

Each of these non-limiting examples may exist independently or may be combined in various permutations or combinations with one or more of the other examples.

The foregoing detailed description includes references to the accompanying drawings, which form a part of the detailed description. Which show by way of illustration specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples". These examples may include elements in addition to those illustrated or described. However, the inventors also contemplate embodiments that provide only those elements shown or described. Moreover, the inventors also contemplate examples using any combination or permutation of those elements (or one or more aspects thereof) shown or described with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

If usage between this document and any document incorporated by reference is inconsistent, then usage in this document controls.

In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more. In this document, unless otherwise stated, the term "or" is used to indicate nonexclusive, or "a or B" includes "a without B," B without a, "and" a and B. In this document, the terms "including" and "in which" are used as the plain-english equivalents of the respective terms "comprising" and "wherein". Furthermore, in the following claims, the terms "comprises" and "comprising" are open-ended, i.e., a system, device, article, composition, formulation, or process that comprises elements in addition to those listed after such term in a claim is considered to fall within the scope of that claim. Furthermore, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The method examples described herein may be implemented at least in part by a machine or computer. Some examples may include a computer-readable or machine-readable medium encoded with instructions operable to configure an electronic device to perform a method as described in the above examples. An implementation of such a method may include code (e.g., microcode, assembly language code, higher level language code, etc.). Such code may include computer readable instructions for performing various methods. The code may form part of a computer program product. Further, in one example, the code can be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer-readable media (e.g., during execution or at other times). Examples of such tangible computer-readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic tape, memory cards or sticks, Random Access Memories (RAMs), Read Only Memories (ROMs), and the like.

The above description is intended to be illustrative and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, for example, by one skilled in the art upon reading the above description. The abstract is provided to comply with 37c.f.r. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the foregoing detailed description, various features may be combined together to simplify the present disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that the examples can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A device for repairing a phalangeal joint, the device comprising:

a first anchor;

a second anchor; and

a flexible spacer connecting the first anchor and the second anchor, the flexible spacer comprising:

a plurality of elongated fibers extending between the first anchor and the second anchor; and

a polymer matrix interspersed with the plurality of elongated fibers,

wherein:

the first anchor is connected to a first end of the flexible spacer by a first interdigitation region of the plurality of elongated fibers and polymer matrix that transitions the porous structure of the first anchor to the flexible spacer; and is

The second anchor is connected to a second end of the flexible spacer by a second interdigitation region of the plurality of elongated fibers and polymer matrix transitioning the porous structure of the second anchor to the flexible spacer.

2. The device of claim 1, wherein the flexible spacer and the first and second anchors are integral with one another.

3. The device of claim 2, wherein the first and second anchors are each comprised of a porous structure.

4. The device of claim 1, wherein the first and second interdigitation regions extend into the apertures of the first and second anchors and are free of fibers of the plurality of elongated fibers.

5. The device of claim 1, wherein the flexible spacer is comprised of a polymer composition and the first and second anchors are comprised of a porous metal structure.

6. The device of claim 1, wherein the flexible spacer comprises fibers of the plurality of elongated fibers in a range of about 20% to about 70% of a volume of the flexible spacer.

7. The device of claim 1, wherein the first and second anchors each comprise one or more fixation staples.

8. The device of claim 1, wherein the fibers of the plurality of elongated fibers are spaced apart from each other by the polymer matrix.

9. The device of claim 1, wherein fibers of the plurality of elongated fibers extend parallel to a central axis of the first and second anchors in an unflexed state.

10. The device of claim 1, wherein fibers of the plurality of elongated fibers extend crosswise relative to each other and to central axes of the first and second anchors in an unbuckled state.

11. A prosthetic metatarsophalangeal joint device, the device comprising:

a metatarsal anchor comprising a porous metal material;

a phalanges anchor comprising a porous metal material;

a polymeric spacer element connecting the metatarsal anchor and the phalanx anchor, the polymeric spacer element including a plurality of elongate fibers extending between the metatarsal anchor and the phalanx anchor;

first and second fixation pins extending from the metatarsal anchor and the phalangeal anchor, respectively;

a polymeric matrix material interspersed with fibers of the plurality of elongated fibers; and

an interdigitation region of a pore tendon of the porous metal material fusing the metatarsal anchor and the phalangeal anchor with a fiber of the plurality of elongated fibers.

12. A method of manufacturing a device for repairing a phalangeal joint, the method comprising:

fabricating a first anchor assembly and a second anchor assembly using a first additive manufacturing process to create a porous structure within each assembly;

fabricating a flexible spacer assembly using a second additive manufacturing process or a molding process to produce a plurality of elongated fibers extending through the flexible spacer; and

attaching opposite ends of the flexible spacer assembly to the first and second anchor assemblies,

wherein fabricating the flexible spacer assembly using the second additive manufacturing process or the molding process comprises:

fusing a first interdigitation region into the first anchor assembly;

building a plurality of elongated fibers from the interbonded regions;

interspersing a matrix layer between fibers of the plurality of elongated fibers;

building a second interbonded region onto the plurality of elongated fibers and the matrix layer; and

fusing the second interdigitation region into the second anchor assembly.

13. The method of claim 12, wherein fabricating the first and second anchor assemblies using the first additive manufacturing process and fabricating the flexible spacer assembly using the second additive manufacturing process or the molding process comprises printing the assemblies from different materials.

14. The method of claim 13, wherein printing the first and second anchor assemblies comprises selective laser sintering from metal powder or electron beam based three-dimensional printing of first and second metal-porous anchor assemblies.

15. The method of claim 13, wherein fabricating the flexible spacer assembly using the second additive manufacturing process comprises three-dimensionally printing or molding the flexible spacer from polyethylene and three-dimensionally printing or molding the flexible spacer to include antibiotic powder or electronic circuitry.

16. The method of claim 12, wherein fabricating a flexible spacer assembly using a second additive manufacturing process or a molding process to create a plurality of elongated fibers extending through the flexible spacer comprises extending the fibers directly through or extending the fibers in an intersecting manner through.

17. The method of claim 12, wherein fabricating the first and second anchor assemblies using the first additive manufacturing process to create the porous structure within each assembly comprises producing a plurality of cellular ribs interconnected to form open spaces.